1. The Field of the Invention
The present invention relates to methods for making high surface area solid catalyst supports and adsorbants having a controlled pore structure.
2. The Relevant Technology
Porous, high surface area metal oxides are used in many applications including thin film semiconductors, solar panels, and as catalyst carriers or “supports” in heterogeneous catalytic systems. Such carriers provide an inexpensive, porous framework for preparation and stabilization of highly-dispersed catalytic phases, i.e., catalytic metals, oxides, or sulfides. The most common catalyst supports consist of the oxides of aluminum, silicon, and titanium. Aluminas (aluminum oxides, Al2O3) are the most widely used commercial catalyst supports because of their excellent thermal stability and wide range of useful chemical, physical and catalytic properties.
Of the different alumina phases, γ-alumina is most often the preferred structure because of its high thermal stability, relatively high surface area, high mechanical strength, and ability to be formed into extrudates or pellets, as compared to many other types of metal oxide structures. However, the properties of commercially available γ-aluminas are limited. Titanias n both the rutile and anatase crystalline phases also have multiple commercial applications. There is a need for methods that can reliably produce γ-aluminas, titanias and other metal oxides with different pore structures than those currently available and that can do so in an economically feasible way. Published methods for synthesizing mesoporous aluminas and for manufacture of conventional alumina, silica, and titania supports typically involve laborious, multi-step procedures which all involve solution-based methods which add substantially to the cost of such materials. And, each method produces a support material with relatively fixed pore structure characteristics. Examples of various supports and procedures for making supports are disclosed in U.S. Pat. Nos. 2,749,216; 2,796,326; 2,917,366; 3,019,080; 3,038,784; 3,042,696; 3,244,972; 3,419,352; 3,823,895; 3,898,322; 3,941,719; 3,944,658; 3,987,155; 4,154,812; 4,172,809; 4,175,118; 4,275,052; 4,387,085; 4,532,072; 4,579,729; 4,676,928; 5,455,019; 5,480,630; 5,593,654; 5,622,684; 5,863,515; 6,001,326; 6,027,706; 6,129,904; 6,555,496; 6,761,866; 6,764,672; 7,090,824; 7,163,963; 7,235,224; 7,341,976; 7,442,290; 7,534,415; and 7,807,605.